Last year I purchased a counterfeit GFB DV+ off of eBay (unintentionally) when I was interested in making a comparison of the stock DV and the stock DV attached to the DV+.
Inconsistent boost bleed-off was recorded with the fake DV+ and after reaching out to GFB they informed me that the unit I was using was counterfeit.
It turns out GFB had a video addressing the fake product issue:
The video does a nice job of showing signs of product differences and mentions that performance with a counterfeit might be off.
I thought it would be helpful to illustrate the difference in the performance of the genuine DV+ versus the counterfeit product that I recorded.
The data from the counterfeit product was recorded with the product when it was brand new.
The data from the genuine GFB DV+ was recorded after 4 months of continuous use and approximately 6 months of total usage.
In the following charts, the boost pressure decay after letting off the accelerator is shown for the genuine DV+ and the fake product.
Note: The GFB DV+ boost pressure trace is very similar to the stock DV shown in the image in the expansion box below.
Comparison of the boost pressure trace from a genuine GFB DV+ and a counterfeit DV+ installed on an IS38+ turbocharger equipped Mk7 GTI is performed.
The genuine GFB DV+ shows an immediate decrease in boost pressure upon activation of the diverter valve in all five samples. The counterfeit DV+ shows inconsistent operation at the opening, with boost pressure spiking approximately 6 psi in 60% of the samples.
The genuine GFB DV+ shows a smooth decrease in boost pressure versus the time the valve is open. The counterfeit DV+ shows boost pressure oscillations of approximately +/- 1 psi in all samples that continue until boost pressure drops to approximately 2-3 psi.
The counterfeit unit was replaced shortly after determining the product was not genuine. How the counterfeit DV+ product performance would change with longer-term use is unknown. One hypothesis is that the sticking would become worse with wear, leading to poorer boost pressure management.